Might be easiest to go out early in the morning while it's still dark and she's still on the roost. When I have to "doctor" my chickens I usually do it at night after they've gone to roost. They don't see well in the dark. I had a cheap little head lamp that had, among other options, a red light. They don't see very well in red light, either, so I could see what I was doing without disturbing them much. I certainly wasn't going to have any success chasing them around the yard, lol! Good luck!
